To translate this code into a concatenative language, we are going to work from the inside and move out. In this case, starting with the sum of the cartesian product of eight sequences of the numbers 0 through 5:

map(sum, product(range(6), repeat=8))

vs.

8 [6 iota ] replicate [ sum ]product-map

Next, we see that it counts each element, and produces a sorted list of items:

sorted(Counter(...).items())

vs.

histogram >alist sort-keys

And finally, prints a line of stars for each element:

print"\n".join('*'*(c//2000) for i,c in...)

vs.

values [2000 /i CHAR: * <string> print ] each

Putting it all together, it makes this nice "ASCII Art" visualization: